Begin Colorectal-Cancer Screening At 45 Years, Not 50, Says USPSTF

The recommended age to begin colorectal-cancer screening should be lowered to 45 years, according to draft recommendations from the U.S. Preventive Services Task Force (USPSTF).

"New science about colorectal cancer in people younger than 50 has allowed the Task Force to recommend that people begin screening at age 45, instead of 50," task force member Dr. Martha Kubik of the College of Health and Human Services at George Mason University, in Fairfax, Virginia, told Reuters Health by email.

The 2016 USPSTF guidelines recommended screening for colorectal cancer starting at age 50 years and continuing until age 75 years. They concluded that the decision to screen for colorectal cancer in adults aged 76 to 85 years should be an individual one and that screening should be discontinued after age 85 years.

Dr. Kubik and USPSTF colleagues used findings from an evidence update to develop updated recommendations. Their recommendations apply to asymptomatic adults who are at average risk of colorectal cancer.

The group concluded with high certainty that there was a substantial net benefit of colorectal-cancer screening in adults aged 50 to 75 years, so it reiterated the previous recommendation to screen all adults in this age group.

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With moderate certainty, the task force concluded that there was a moderate net benefit of screening for colorectal cancer in adults aged 45 to 49 years, so it lowered the age to initiate screening to 45 years.

The net benefit of screening in patients aged 76 to 85 years is smaller than in the other age groups, so USPSTF recommends selective screening in this age group, based on the patient's overall health and prior screening history. Adults in this age group who have never been screened for colorectal cancer are most likely to benefit.

These recommendations apply to stool-based tests with high sensitivity, colonoscopy, CT colonography and flexible sigmoidoscopy, although the recommended intervals for screening differ according to the test.

The draft recommendations suggest annual screening with stool-based tests, CT colonography every five years, flexible sigmoidoscopy every five years, flexible sigmoidoscopy every 10 years plus annual stool-based testing, or colonoscopy screening every 10 years.

"The Task Force looked for evidence that would have supported a separate recommendation on colorectal-cancer screening in Black adults but found that there was limited research available," Dr. Kubik said. "We are calling for more research on the factors that contribute to this disproportionate risk and encourage increased efforts to ensure that Black communities receive high-quality care."

"Colorectal cancer is a devastating disease and is the third leading cause of cancer deaths in the United States," she said. "Black adults get colorectal cancer more often and are more likely to die from colorectal cancer than people of other races and ethnicities. The Task Force strongly encourages clinicians to ensure that their Black patients receive recommended colorectal cancer screening, and appropriate follow-up, beginning at age 45."

"Screening for colorectal cancer saves lives," Dr. Kubik said. "There are many effective screening tests available, and patients should talk to their clinician about which option may be best for them."

Dr. Lise M. Helsingen of the University of Oslo, in Norway, and Frontier Science Foundation, in Boston, Massachusetts, who recently coauthored a guideline on colorectal-cancer screening, told Reuters Health by email, "There is no data from randomized trials supporting to lower the start age of screening from age 45 to 50. This age shift in recommendations is based solely on modeling estimates with large uncertainties."

"Even though observational data suggests that the incidence of cancer screening among people aged 40 to 49 has increased slightly over the last two decades, the incidence of colorectal-cancer screening in those below 50 is still small, and hence, so are the absolute benefits of screening in this age group," she said.

"There is a fine balance between the potential benefits versus the burdens and harms of colorectal-cancer screening," Dr. Helsingen said. "Even though some people may benefit, every screening participant will experience some degree of burden associated with the procedure, and some may even be harmed. How people will weigh these potential benefits versus the burdens and harms will likely vary largely among screening-eligible people, and I therefore believe that strong recommendations for or against colorectal cancer screening are inappropriate."

The draft recommendation statement, the evidence synthesis, and responses to frequently asked questions are available on the USPSTF website. The draft recommendation is available for public comment for four weeks from October 27 to November 23, 2020.

—Will Boggs MD

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